Vacuum Advance for EA81T

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coronan
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Vacuum Advance for EA81T

Post by coronan » Thu May 05, 2016 7:27 am

Hello,

My 84 brat has stock turbo. I can not find a Replacement advance / retard diaphragm in the US. Some fruit cakes who said they could build it are having trouble.

I'm not ready for EDIS. (Don't have time)

I wanted to see if you folks on the other side of the pond have found a solution.
Maybe a similar part from another application?

Thanks!

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steptoe
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Post by steptoe » Thu May 05, 2016 7:36 am

have you found the original subaru part number ? There is a chance that the EA82T Series 1 may have used the same part. They were still available some years back, bit over A$230

Someone in Brisbane ? Queensland advancediapragmoptions ? rebuilt one for Discopotato03 some years back, about A$80

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coronan
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Post by coronan » Thu May 05, 2016 8:02 am

I can get a complete distributor for ~$200. But I only need a $20 vacuum diaphragm.

If it comes down to a new Dizzy i'd rather spend the money on EDIS. I'm not sure yet but I believe EDIS would cost $ 300 - 400.

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Post by El_Freddo » Fri May 06, 2016 8:01 pm

I'd imagine it'd be basically the same as the early 3 plug/flapper Afm EA82 turbo vac advance setup.

If you can find part numbers to compare you should be able to work out if this part I'm talking about will work for you - then you might be able to pick up a decent second hand unit. Or we. Compare it to other early 80s turbo setups...

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TOONGA
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Post by TOONGA » Sat May 07, 2016 11:05 am

Not sure if this is the same one from Ebay Australia refurbished

http://www.ebay.com/itm/Hitachi-Vacuum- ... Kw&vxp=mtr

or this one from Israel new from Subaru

http://www.ebay.com/itm/SUBARU-1976-84- ... 9g&vxp=mtr

or this distributor from the USA remanufactured

http://www.ebay.com/itm/ARROW-55-5247-3 ... 36&vxp=mtr

Good luck with it

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coronan
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Post by coronan » Thu May 12, 2016 4:14 am

The first 2 links are for naturally aspirated cars.
The 3rd is for Dual port.

Here is a photo of my stock unit.

Image

I'm still not sure if it provides Only Retard on Boost as the base timing is 16* BTDC in the book.

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Post by steptoe » Thu May 12, 2016 8:38 am

it would be a guess that the EA82T dizzy can is a flow on product from the EA81T as a lot of EA82T first series looks like EA81T stuff. Yours shot? no hold vacuum ? I wonder if you put a std NA one side by side and compared. Never pulled one apart but figure diafragm is in the middle in line with the fold over seam, then one chamber for a spring. An NA might look like one spring chamber, a boost/retard might have a chamber back and front. It may not be a $20 unit due to its uniqueness ? And you'd think if it has both functions you'd feel spring resistance both ways yeah ? Just popped into my bathroom and ripped the vac can from my ea82T dizzy, can blow through so is razzed, has no visible numbers or markings and using my j.rabone best box timber rule [shows how far back have to go to find an inch measuring device :) ] 1 3/4" from centre to centre of holes you look to have measured.

Certainly has spring resistance pusging shaft into can, and very short stronger to pull out just a few mm [guess]

Also gues that if you install your can in dizzy and see if the dizzy plate can rotate both directions to provide retard?

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steptoe
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Post by steptoe » Thu May 12, 2016 8:57 am

HITACHI AUTO PART 70139684 44R83-44003

was under the Subaru part label when I pawned a testicle

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Post by steptoe » Thu May 12, 2016 9:05 am

now, did you follow up my suggestion above or was I wasting my breath?

done some more work

https://www.facebook.com/AdvanceDiaphragmOptions/

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Post by coronan » Thu May 12, 2016 9:33 am

No my Vacuum Pod does not hold vacuum. I sent it to the state side "expert" who said he can't rebuild it, and its unique.

I tried looking for EA82T Dizzy parts (85-86) in RockAuto's Catalog. No success on vacuum pods. Turbo or otherwise.

Rockauto says the Distributor does not cross over. Different part numbers for 83-84 and 85-86.

Hard to tell if if pushes and pulls being that it's broken. It would be great to find out the throw retract. I is single chamber but could flex the diaphragm both ways.

Here is what the N.A. vacuum pod looks like.
Image

Completely different. Its missing the tapped mounting hole and has a different length arm. And probably not provide retard on boost.


HITACHI AUTO PART 70139684 44R83-44003 returns ZERO search results in google.

I'll have a look at my dizzy. I may not be able to tell anything until i get the vacuum pod back from the "expert".

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Post by steptoe » Thu May 12, 2016 12:48 pm

Yep, completely understandable that the EA81T whole assy did not cross over to the EA82T but possibly the module inside is 4 pin and has a knock control module remote ? Your can measures up same so far as my EA82T can and I know that the guy in link above has rebuilt one for discopotato3 on here - they needed some measures from mine to finish off. Your can looks like mine to and I suspect your diaphragm may just have a hole in it which makes it broken, but the break does not change its spring loading either way boost or retard as far as I can recall - have dismantled a few - never to be rebuilt

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Post by steptoe » Thu May 12, 2016 11:07 pm

read the third post from the top by naru

http://www.ultimatesubaru.org/forum/top ... -question/

might answer some questions re interchange of EA81T and EA82T dist bits :)

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Post by coronan » Thu May 12, 2016 11:27 pm

Those guys are Talking about N.A. Cars and Honda Vacuum pods. Same as the ones mentioned in post 5 by TOONGA. I have raised my case in post 12.

Ultimatesubaru is a great resource with a US base. But i'm not getting anywhere so i came to the AU forum.

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Post by steptoe » Fri May 13, 2016 8:58 am

*cough * cough

can I spell it out for you ?

to quote the post by naru I am refering to

"I bought a complete ea-82 turbo dizzy in order to get an ea-81 turbo vac advance.Spare ignition module was a bonus.
Complete dizzy is probably only a few more bucks"

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coronan
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Post by coronan » Fri May 13, 2016 9:40 am

I saw that.
If A complete dizzy is $200. How much more is EDIS?
The Pickup is already in the Turbo Dizzy.

There are 2 things i haven't found when reading EDIS conversions.
1 no one is using the Turbo Dizzy for a pickup.
2 No one is using the factory MPFI
3 little to no boosted applications. And definitely not with out full aftermarket ECU.

I'd like a simple EDIS swap and retain the stock ECU.

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coronan
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Post by coronan » Fri May 13, 2016 10:21 am

From Advanced Diaphragm Options
Thanks for the photo.
It is clearly not the same as any model that we have here in Aus.
We can definitely reco that unit. You will need to send it to us.
Cost would be $85au plus freight each way.

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Post by steptoe » Fri May 13, 2016 11:24 am

Good, What I saw in it was that the EA82T vac can and module will work in EA81T

on the megajoltE I see they have up to 3 bar MAP sensor, so that should cover boost such as turbo. You may just be a pioneer doing an EDIS on EA81T

I am wondering out loud if/how the MegajoltE EDIS can use a knock sensor input. My EA82T has a knock sensor, 1 wire for later, two wire for earlier EA82T
I get impression is if you try to hook up a dizzy for its optical pick up you may be on your own for working out how to wire it in. If you go complete EDIS set up that everyone in their community go, you are on same level - a 36-1 tooth ring on the crank pulley, a universal pick up you need to make a bracket for, universal generic coils etc

Advance has not put prices up in ten years !

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Post by steptoe » Fri May 13, 2016 11:51 am

well, if we can trust that naru found EA81T worked well with the EA82T vac can ...spoke to Mike of advance which is a father and son concern, I could send my good newish one to him to measure up for specs, so you would get an EA82T spec unit as in spring tensions etc. Says he could likely build you one based on it, instead of you posting yours to him.

Hows that sound?

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Post by Silverbullet » Fri May 13, 2016 7:04 pm

coronan wrote: There are 2 things i haven't found when reading EDIS conversions.
1 no one is using the Turbo Dizzy for a pickup.
2 No one is using the factory MPFI
3 little to no boosted applications. And definitely not with out full aftermarket ECU.

I'd like a simple EDIS swap and retain the stock ECU.
I've converted my EA81 to EDIS as has another member on here (SubyDoug) and although mine isn't turbo I can probably answer a few of these points. Keep in mind there are 2 aftermarket EDIS conversion systems that I know of - Megajolt and Megasquirt. I use the jolt, it only controls ignition. The squirt does ignition in much the same way, but can also control fuel injection.

1 - I wouldn't say nobody is using an original dizzy as a pickup, just very few. Main reason I see to not use it would be you still have moving, wearing parts that can introduce "play" and innacuracy into an otherwise precision ignition system. Also the signals the stock dizzy puts out might not be what the EDIS ECU is looking for as a trigger (I couldn't say yes or no, I don't know what the stock dizzy puts out)

2 - You could use the factory MPFI with either EDIS system. For the megajolt system you could leave the MPFI untouched, but the megajolt ECU is still required and is a separate, standalone unit. If you went megasquirt, it would seem a waste to me to not control the MPFI with it as well. Still it is a separate ECU unit (not sure if you could omit the stock ECU in this case? I'm guessing not, and it definitely wouldn't be a simple weekend swap job)

3 - I'm pretty sure there are people who have had great success putting EDIS on a boosted engine. You might need something other than the built in MAP sensor on the megajolt, or have a throttle position sensor instead (you can run it with one or the other) The main benefit of EDIS was to those with older (i.e non boosted) engines who want to ditch their crappy old dizzy.

Which ever option you go, EDIS being a "simple swap" is a matter of perspective :rolleyes: Definitely not as simple as just getting a vacuum can rebuilt/replaced for your old dizzy, but definitely a much better system overall. As for cost, I couldn't say for you in another country (where cars with stock EDIS e.g 90's fords were more common, handy to nick parts from) but for me it's probably up there around the $500 AUD mark and that was having to buy every individual part in from overseas. The megajolt ECU is even made in the states! Another thing worth mentioning; if you do the EDIS swap it isn't as easy as bolting the parts in and go. The installation is 75% of the work, tuning it and creating a good ignition map for your particular engine makes up the rest.

Oops, sorry if I completely derailed this thread about EA81T vacuum cans and making a wall of text :oops: Hopefully it can help you decide which way to go though.
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Post by El_Freddo » Fri May 13, 2016 10:59 pm

That's a good explication SB ;)

Big move for a "measly" vacuum canister.

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